A nitride semiconductor device including a light emitting device comprises a n-type region of one or more nitride semiconductor layers having n-type conductivity, a p-type region of one or more nitride semiconductor layers having p-type conductivity and an active layer between the n-type region and the p-type region. In such devices, there is provided with a super lattice layer comprising first layers and second layers which are nitride semiconductors having a different composition respectively. The super lattice structure makes working current and voltage of the device lowered, resulting in realization of more efficient devices.

Nitride semiconductor device

A nitride semiconductor laser device has an improved stability of the lateral mode under high output power and a longer lifetime, so that the device can be applied to write and read light sources for recording media with high capacity. The nitride semiconductor laser device includes an active layer, a p-side cladding layer, and a p-side contact layer laminated in turn. The device further includes a waveguide region of a stripe structure formed by etching from the p-side contact layer. The stripe width provided by etching is within the stripe range of 1 to 3 μm and the etching depth is below the thickness of the p-side cladding layer of 0.1 μm and above the active layer. Particularly, when a p-side optical waveguide layer includes a projection part of the stripe structure and a p-type nitride semiconductor layer on the projection part and the projection part of the p-side optical waveguide layer has a thickness of not more than 1 μm, an aspect ratio is improved in far field image. Moreover, the thickness of the p-side optical waveguide layer is greater than that of an n-side optical waveguide layer.

Nitride semiconductor laser device

An optical sensor diagnostic system utilizing a tunable Vertical Cavity Surface Emitting Laser (VCSEL) that incorporates an integrated MEMS tuning mechanism provides variable wavelength light into an optical fiber with improved wavelength scanning speed and greater simplicity of construction. Sensors, such as Bragg gratings, are disposed along the fiber in the light path. Each sensor reflects or transmits light exhibiting a characteristic amplitude feature with respect to wavelength, the wavelength position of which is affected by an environmental stimulus imposed thereon. The power of the reflected light is converted to an electrical signal by a simple detector and monitored by circuitry that detects changes in reflected power and provides output signals indicative of the environmental stimulus for each sensor.

System and method for measuring physical, chemical and biological stimuli using vertical cavity surface emitting lasers with integrated tuner

An optical header for coupling a light source to an optical fiber is disclosed. The header preferably includes a ceramic substrate that has a recess for a vertical cavity surface emitting laser (VCSEL), or alternatively an edge emitting laser. An optical fiber is preferably attached to a ceramic substrate and terminates at a light source. The end of the fiber is preferably cleaved or polished to an angle such that light entering the fiber from the light source is substantially reflected into the fiber. A reflective coating is placed on the cleaved end of the fiber thereby permitting a small percentage of light to radiate away from the fiber and toward an intensity detector. The light preferably travels to the detector through a transmission medium such as a prism or an optical-grade epoxy. The header is particularly useful when used in conjunction with multiple fibers simultaneously to form an optical fiber array. The header is also useful to house an optical receiver, or to form a bi-directional header suitable for fiber optic communications.

Fiber optic header with integrated power monitor

A wavelength converter assembly includes a substrate An epitaxial structure is formed on the substrate with areas of different optical properties A laser and a photodetector are formed in the epitaxial structure The photodetector generates a first electrical signal in response to an optical signal A conditioning circuit is coupled to the laser and the photodetector The conditioning circuit receives the first electrical signal and provides a second electrical signal to the laser to modulate its optical output

Integrated opto-electronic wavelength converter assembly

An integrated laser-based light source that generates an output light beam having a controlled intensity. The light source comprises a light sensor, a laser, a convex beam-splitting surface, and a package that includes a header. The light sensor generates an electrical signal representing an intensity of light energy falling on it, and is mounted on the header. The laser has one and only one light-emitting face from which a light beam is radiated as a radiated light beam. The laser is mounted in the package adjacent the light sensor with the light-emitting face substantially parallel to the light-receiving face of the light sensor. The convex beam-splitting surface reflects a fraction of the radiated light beam towards the light sensor as a reflected light beam, and transmits the remainder of the radiated light beam as the output light beam. The convex beam-splitting surface is supported in the radiated light beam by the package.

Laser-based controlled-intensity light source using reflection from a convex surface and method of making same

An integrated laser-based light source that generates an output light beam having a controlled intensity. The light source comprises a package, a laser, a light sensor, and a beam splitter. The beam splitter is mounted in the package, together with the laser and the light sensor. The laser has one and only one light-emitting face from which it radiates a light beam as a radiated light beam. The light sensor generates an electrical signal representing the intensity of light energy falling on it. The beam splitter divides the radiated light beam into a fraction and a remainder, the remainder being the output light beam. The beam splitter operates by diffraction, scattering, or transmission to direct the fraction of the radiated light beam towards the light sensor.

Integrated controlled intensity laser-based light source using diffraction, scattering and transmission

An integrated laser-based light source that generates an output light beam having a controlled intensity. The light source comprises a package in which are mounted a laser, a light sensor and a coupler. The laser has one and only one light-emitting face from which a light beam is radiated as a radiated light beam. The light sensor generates an electrical signal representing the intensity of light energy falling it. The coupler couples a fraction of the radiated light beam to the light sensor, and provides the remainder of the radiated light beam as the output light beam. Since the light coupled to the light sensor by the coupler is a fraction of the radiated light beam, the electrical signal generated by the light sensor also represents the intensities of the radiated light beam and of the output light beam. A suitable control circuit, when fed with the electrical signal generated by the light sensor, can control the laser current to hold the electrical signal generated by the light sensor to a predetermined value that corresponds to the output light beam having a predetermined intensity.

Integrated controlled intensity laser-based light source

Laser based light source using scattering

An integrated laser-based light source (300, 320, 340, 350, 500), which generates an output light beam (119) having a controlled intensity, comprises a light sensor (111, 351), a laser (101), a convex beam-splitting surface (345, 545), and a package (105, 501) that includes a header (103). The light sensor generates an electrical signal representing an intensity of light energy falling on it, and is mounted on the header. The laser has one and only one light-emitting face (109) from which a light beam is radiated as a radiated light beam (107). The laser is mounted in the package adjacent the light sensor with the light-emitting face substantially parallel to the light-receiving face of the light sensor. The convex beam-splitting surface reflects a fraction of the radiated light beam towards the light sensor as a reflected light beam, and transmits the remainder of the radiated light beam as the output light beam. The convex beam-splitting surface is supported in the radiated light beam by the package.

Tao Zhang

Papers

Laser-based controlled-intensity light source using reflection from a convex surface and method of making same

Integrated controlled intensity laser-based light source using diffraction, scattering and transmission

Integrated controlled intensity laser-based light source

Laser based light source using scattering

Laser-based light source